A steering column apparatus is an important safety-maintaining part of a vehicle. In order to secure safety of a passenger in the crash time, how to control the motion of the steering column apparatus in the crash time is very important. Generally, the steering column apparatus itself is provided with an impact energy absorbing mechanism, and also performs an important part as a support member of an air bag housed in a steering wheel.
Further, in order to make a drive posture of a driver most appropriate, a general steering column apparatus, in accordance with driver's physical build and drive posture, can adjust an inclined angle of a steering wheel and can adjust a position in an axial direction of the steering wheel. Accordingly, the steering column apparatus must adjust readily the position and posture of a column body (i.e., steering wheel), and also must secure the predetermined position and posture of the column body in the crash time. Namely, the steering column apparatus requires these conflicting functions. In order to reconcile such the conflicting functions, the conventional steering column apparatus has exerted much ingenuity. However, due to increase in request for operational ease of the user, the steering column apparatus requires more improvement.
Here, in Patent Document 1, a steering column apparatus has been disclosed, which can hold a column body by means of friction force generated between superimposed many frictional plates.
Patent Document 1: JP-A-10-35511
Patent Document 2: German Patent DE-B-10212263
Patent Document 3: U.S. Patent Application Unexamined Publication 2005/0016315A1